Most Helpful Guy
I can't imagine what would happen to it in a year. Colossal toxin breakdown? Research it, you've got the internet.
Most Helpful Girl
It should be, as long as it was properly sealed and not disgusting (messy/oily/dirty etc); powder foundations are dry and can be kept longer than a year if you still have product left to use.
"Anything cream-based (foundation, blush or shadows) last from about 12 to 18 months. Since they contain oil, they tend to break down faster than powder formulas, which can last about two years. Lipstick expires after a year, while gloss will make it to the 18-month mark. Eye makeup has a decidedly shorter existence."